| 摘要 |
PROBLEM TO BE SOLVED: To provide a write-once optical recording medium in which information is recorded and reproduced by the phase transition of a recording material by irradiation with laser light and in which the change rate of reflectance due to the phase transition from an amorphous phase to a crystal phase is increased to increase the CN ratio of the reproduced signals and to obtain excellent storage property for a long time of the information. SOLUTION: A first dielectric layer 12 of a ZnS-SiO2 layer, a recording layer 14 of a AgInSbTe layer with addition of N, a second dielectric layer 16 of an AlN layer, and a reflection layer 18 of an Al-Ti layer are formed on a transparent substrate 10 made of a polycarbonate substrate in this order. The product of the refractive index (n) and the layer thickness(d) of the second dielectric layer 16 satisfies (nd)>130 nm so that the reflectance Ra of the amorphous phase region and the reflectance Rc in the crystal phase region in the recording layer 14 always have the relation of Ra>Rc. |
